This invention relates generally to the field of collapsible shipping containers and more particularly to an improved system using containers of this type when shipping particular types of cargo.
In the transporting of particulate comestible material, such as sugar, flour, raisins, wheat grain and the like, it is conventional to package the same in large sacks of textile or synthetic resinous material for shipment. In some cases, the sacks are provided with ring means permitting engagement with overhead carrier means so that emptying of the sacks is accomplished by moving the sacks over a hopper or other receptacle following which the sack is cut on an undersurface thereof to provide an opening through which the contents flow under the action of gravity. Once emptied, the sack is discarded.
This means of transport is not without utility. However, there are accompanying disadvantages. The loaded sack is not rectangular in configuration, and thus cannot be stacked in a transporting vehicle for maximum space utilization. They cannot be readily moved by a forklift. Since the bags are totally unshielded, they are subject to puncture and accompanying loss of contents. The outer surfaces of the sacks become contaminated by contact with other objects during shipments, and can release foreign material with the cargo when it is empty. In the case of liquid materials, the result of puncture is usually the loss of the entire contents of the sack.
In the case of edible products, the principal justification of the use of sacks lies in low container cost, and the ability to discard containers after a single use.